Hum… sorry but I don't like it very much.
I guess it's quite difficult to render properly the feeling you get there, with the depth of the sky literally forced on you. BTW, maybe that's not what you tried to achieve, focusing more on the “flat” feeling and the light contrasts. The one on the circle border is great, but I find the whole picture quite uninteresting.

Strangely, the more I look at it, the less I dislike it… (maybe because it reminds me of some Samael cover art). But definitely not the best of what you're capable of.
C'est mon dernier mot Jean-Pierre ^_^